﻿// Copyright 2004-2009 Castle Project - http://www.castleproject.org/
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//     http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#region 导入名称空间

using System.Threading;

#endregion

namespace LightWork.DynamicProxy.Internal
{
    internal class SlimReadWriteLock : Lock
    {
        private readonly ReaderWriterLockSlim locker = new ReaderWriterLockSlim(LockRecursionPolicy.NoRecursion);

        public bool IsReadLockHeld => locker.IsReadLockHeld;

        public bool IsUpgradeableReadLockHeld => locker.IsUpgradeableReadLockHeld;

        public bool IsWriteLockHeld => locker.IsWriteLockHeld;

        public override IUpgradeableLockHolder ForReadingUpgradeable()
        {
            return ForReadingUpgradeable(true);
        }

        public override ILockHolder ForReading()
        {
            return ForReading(true);
        }

        public override ILockHolder ForWriting()
        {
            return ForWriting(true);
        }

        public override IUpgradeableLockHolder ForReadingUpgradeable(bool waitForLock)
        {
            return new SlimUpgradeableReadLockHolder(locker, waitForLock,
                locker.IsUpgradeableReadLockHeld || locker.IsWriteLockHeld);
        }

        public override ILockHolder ForReading(bool waitForLock)
        {
            if (locker.IsReadLockHeld || locker.IsUpgradeableReadLockHeld || locker.IsWriteLockHeld)
                return NoOpLock.Lock;

            return new SlimReadLockHolder(locker, waitForLock);
        }

        public override ILockHolder ForWriting(bool waitForLock)
        {
            if (locker.IsWriteLockHeld)
                return NoOpLock.Lock;

            return new SlimWriteLockHolder(locker, waitForLock);
        }
    }
}